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50mm Celotex CW4050 Cavity Wall Insulation Board 1200mm x 450mm (5.94m2/Pack)
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Mon 22 Jun
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- 8hrs
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| 10+ packs | 10+ packs | 15+ packs |
| £68.49ex. VAT | £67.84ex. VAT | £65.76ex. VAT |
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Nationwide Delivery
Mon 22 Jun
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- 8hrs
- 32mins
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- Choose Clearpay at checkout to pay later with Pay in 4.
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Clearpay is unregulated credit. Use responsibly. 18+, T&Cs and late fees apply at clearpay.co.uk/en-GB
Clearpay lends you a fixed amount of credit so you can pay for your purchase over 4 instalments, due every 2 weeks. Ensure you can make repayments on time. You must be 18+ and a permanent UK resident (excl Channel Islands). Clearpay charges a £6 late fee for each late instalment and a further £6 if it’s still unpaid 7 days later. Late fees are capped at £6 for orders under £24 and the lower of £24 or 25% of the order value for orders over £24. Missed payments may affect your ability to use Clearpay in the future and your details may be passed onto a debt collection agency working on Clearpay’s behalf. Clearpay is credit that is not regulated by the Financial Conduct Authority. T&Cs and other eligibility criteria apply at clearpay.co.uk/terms
Delivery & Returns Information
Delivery charges vary by product category and order value. Items may ship from different suppliers and arrive separately, so delivery charges can be shown per part of your order at checkout.
Standard (Nationwide) Delivery
| Insulation, Plasterboard and Drylining Products | |
|---|---|
| ORDER VALUE | DELIVERY CHARGE |
| Under £400 | £45 ex. VAT |
| Over £400 ex. VAT | FREE |
Express Delivery
| Express Delivery - Insulation and Plasterboard & Drylining | |
|---|---|
| ORDER VALUE | DELIVERY CHARGE |
| Under £400 | £90 ex. VAT |
| Over £400 ex. VAT | £55 ex. VAT |
| Express Delivery - Timber & Sheet, Building Materials, Joinery and Gardens & Landscaping Products | |
| ORDER VALUE | DELIVERY CHARGE |
| Under £300 | £50 ex. VAT |
| Over £300 ex. VAT | £35 ex. VAT |
How delivery works
We work with a nationwide network of trusted suppliers. Items in your basket may be supplied by different suppliers and delivered separately. Where this applies, you will see delivery charges shown at checkout for each part of your order. We always aim to group products from the same supplier to keep delivery costs as low as possible.
Delivery areas
Delivery charges apply to mainland UK, excluding: AB, CA, CF, DD, DG, EH, EX, FK, KA, KW, KY, IV, LA, LD, LL, ML, NP, PA, PH, PL, SA, SY, TR, TQ and TD.
If your address is in one of these areas, we will contact you before processing your order to confirm any additional costs. We do not currently offer delivery outside the UK mainland.
What to expect on delivery day
- Deliveries are typically kerbside.
- Please ensure someone is on-site to accept delivery. For heavier items, help with offloading may be required.
- Many building materials arrive on large vehicles. If access is restricted, a specialist vehicle such as a HIAB may be required and could incur an additional charge.
Why delivery can cost more than typical parcel delivery
Building materials often travel on larger vehicles and usually carry fewer drops per run than parcel networks. That is why delivery charges can be higher than standard e-commerce shipping.
Returns
Returns depend on what you have bought and whether there is anything wrong with it. For full details on eligibility, timeframes, and exclusions, please see our full policy.
Key Features
- {{home}} Low Global Warming Potential (GWP)
- {{public}} Zero Ozone Depletion Potential (ODP)
Technical Specification
| URN: | 3002014 |
|---|---|
| Brand: | Celotex |
| Application: | Partial Fill Cavity Wall |
| Material Type: | PIR (Polyisocyanurate) |
| Thickness: | 50mm |
| Width: | 450mm |
| Length: | 1200mm |
| Weight: | 11.4kg |
| Sales Unit: | Pack |
| Sales Unit Coverage: | 5.94m2 |
| Pieces Per Pack: | 11 |
| Fire Rating: | Euroclass F |
| Thermal Conductivity: | 0.022W/mK |
| Compressive Strength: | 120kPa |
| Certification: | BBA Approved (24/7312) |
| Facing: | Low Emissivity Foil (Both Sides) |
| Edge: | Square |
| Manufacturer's Reference: | CW4050 |
Technical Downloads
Product Overview
Celotex CW4050 Cavity Wall Insulation Board measuring 50mm thick and 1200mm × 450mm in size.
High-performance rigid polyisocyanurate (PIR) insulation board designed for use in masonry cavity wall constructions. The board provides excellent thermal performance while maintaining a lightweight, easy-to-handle format for quick installation.
Manufactured with a low-emissivity foil facing on both sides, it enhances the thermal resistance of air spaces within the cavity, contributing to improved overall wall U-values. The PIR core delivers reliable long-term stability and moisture resistance, ensuring consistent insulation performance over the building’s lifespan.
The 50mm thickness fits 75mm cavities, maintaining a 25mm residual gap for ventilation and moisture control.
Features & Benefits
- High thermal efficiency: PIR core achieves low thermal conductivity for superior insulation performance.
- Foil facings: Low-emissivity aluminium facings improve cavity reflectivity and reduce heat loss.
- Lightweight design: Easy to cut and fit between wall ties, reducing installation time and waste.
- Moisture resistance: Closed-cell structure minimises water absorption for reliable in-cavity performance.
- Durability: Rigid board maintains dimensional stability and compressive strength during installation.
- Thickness: 50mm board fits 75mm cavities, maintaining a 25mm residual gap for ventilation and moisture control.
Applications
- Masonry cavity walls: Designed for use between inner and outer leaves of traditional brick and block construction.
- Partial-fill systems: Suitable for retaining an air gap while improving overall wall insulation.
- New build and refurbishment: Applicable for both domestic and commercial building envelopes.
- Energy efficiency upgrades: Reduces heat loss and improves compliance with current building regulations.
Installation Guidance
- Preparation: Ensure wall cavities are clean, free from mortar droppings, and dry prior to installation.
- Board placement: Fit boards between wall ties in a staggered pattern with tight-fitting joints.
- Fixing method: Use retaining clips to secure boards against the inner leaf as construction progresses.
- Joint sealing: Tightly butt all edges; tape or seal where specified to prevent thermal bridging.
- Protection: Keep boards dry on-site and avoid exposure to prolonged sunlight.
Compliance & Performance
- Material specification: Rigid polyisocyanurate (PIR) insulation with aluminium foil facings both sides.
- Thermal conductivity: 0.022 W/m·K.
- Fire performance: Class E reaction to fire (BS EN 13501-1).
- Water vapour resistance: Foil facing provides high resistance to moisture ingress.
- Compressive strength: Typically exceeds 120 kPa at 10% compression.
- Environmental compliance: Manufactured under ISO 14001 with zero ODP and low GWP blowing agents.
- Important note: Installation must follow Celotex guidance to maintain declared thermal performance.
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